STRATEGY CALCULATION FOR PHASING PROTEIN CRYSTAL STRUCTURES IN THE PRESENCE OF R

R 存在下定相蛋白质晶体结构的策略计算

• 批准号: 8169921
• 负责人: ANA M GONZALEZ
• 金额: $ 0.27万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8169921
• 关键词: Binding Proteins; Computer Retrieval of Information on Scientific Projects Database; Data; Data Analyses; Data Collection; Data Quality; Development; Disulfides; Dose; Elements; Funding; Future; Grant; Institution; Measurement; Methylobacillus; Muramidase; Noise; Nucleotides; Phase; Proteins; Radiation; Research; Research Personnel; Resources; Site; Source; Structure; United States National Institutes of Health; research study; trend

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Although there is evidence that the energy chosen for data collection does not have a great deal of effect in the global quality of the data [Shimizu, Hirata, Hasegawa, Ueno & Yamamoto (2007) J. Synchrotron Radiat. 14 4-10], the effects of local radiation damage at different energies have not been sufficiently studied. Experiments were undertaken to study the reduction rate of disulfide bridges at 9 and 14.5 keV on HEWL lysozyme. The damage to disulfide bridges happens relatively quickly and it is easy to observe and quantify, and the radiation damage mechanism is thought to be the same as for other elements. Measurements from different crystals indicate that the rate of reduction per dose unit of the disulfide bridges is site depending, with more exposed sites showing an increased rate of decay. Careful analysis of the data suggest that the site decay per dose unit is overall slightly faster at the higher energy. The experiment was repeated for a Se-MET substituted nucleotide binding protein from methylobacillus Flagellatus. The decay for the Se-MET sites also appears faster at higher energy, but in this case the trend was not so clear and could be attributed to noise in the data. These results point to a flaw in the way dose is calculated for crystal diffraction experiments and provide the path for future developments.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 尽管有证据表明，选择用于数据收集的能量对数据的整体质量没有很大影响[Shimizu，Hirata，Hasegawa，Ueno & Yamamoto（2007）J. Synchrotron Radiat. 14 4-10]，不同能量下局部辐射损伤的影响尚未得到充分研究。 实验研究了在9和14.5keV能量下HEWL溶菌酶对二硫键的还原速率。 二硫键的损伤发生相对较快，易于观察和量化，辐射损伤机制被认为与其他元素相同。不同晶体的测量结果表明，每剂量单位的二硫键的还原速率取决于部位，暴露部位越多，衰变速率越高。对数据的仔细分析表明，在较高能量下，每剂量单位的部位衰减总体上略快。对来自鞭毛甲基杆菌的Se-MET取代的核苷酸结合蛋白重复该实验。Se-MET位点的衰减在较高能量下也看起来更快，但在这种情况下，趋势不是那么清楚，可能归因于数据中的噪声。这些结果指出了晶体衍射实验中剂量计算方法的缺陷，并为未来的发展提供了途径。